Known submersible pumps have a large number of precision components which require precise alignment, assembly and interaction among one another. Such known submersible pumps comprise a pump housing, a motor part having an electric motor arranged in a motor housing and having a hydraulic part with a pump wheel as well as having a shaft leadthrough which is arranged between the motor part and the hydraulic part and which is passed through by a rotor shaft.
The submersible pump pumps a pump fluid, for example a water or a waste water, wherein a gas, in particular a flammable gas, which can be distributed about the submersible pump, can arise in dependence on the use of the submersible pump, for example in fermentation processes. On operating disturbances, overheating may arise and ignition sources can be produced in the pump, for example due to spark formation on a short-circuit. If these sparks escape from the pump, they can ignite the gas and damage or destroy the structure in which the pump is installed, such as the pump, and the submersible pump. Submersible pumps can thus only be operated in environments with a flammable atmosphere with special protective measures for safety reasons.
A submersible pump is described in EP 2 249 042 A1 which at least partly surrounds a support tube with an insulating peripheral protective jacket so that a part region of the support tube is insulated thermally and by material from the environment, in particular from the pump fluid and the gas. Such a protective jacket can in particular be provided in the region of a bearing arrangement so that a direct insulation of the particularly risk-intensive bearing region is present. Other measures provide the formation of a gap in the bearing arrangement, for example between a bearing flange and a bearing cover.